Add functions related to thermal neutron peak. Refs #6018.

Code/Mantid/Framework/CurveFitting/CMakeLists.txt

@@ -66,6 +66,9 @@ set ( SRC_FILES
 	src/StretchExp.cpp
 	src/StretchExpMuon.cpp
 	src/TabulatedFunction.cpp
+	src/ThermalNeutronBk2BkExpAlpha.cpp
+	src/ThermalNeutronBk2BkExpBeta.cpp
+	src/ThermalNeutronBk2BkExpSigma.cpp
 	src/ThermalNeutronBk2BkExpConvPV.cpp
 	src/ThermalNeutronDtoTOFFunction.cpp
 	src/UserFunction.cpp
@@ -149,6 +152,9 @@ set ( INC_FILES
 	inc/MantidCurveFitting/StretchExp.h
 	inc/MantidCurveFitting/StretchExpMuon.h
 	inc/MantidCurveFitting/TabulatedFunction.h
+	inc/MantidCurveFitting/ThermalNeutronBk2BkExpAlpha.h
+	inc/MantidCurveFitting/ThermalNeutronBk2BkExpBeta.h
+	inc/MantidCurveFitting/ThermalNeutronBk2BkExpSigma.h
 	inc/MantidCurveFitting/ThermalNeutronBk2BkExpConvPV.h
 	inc/MantidCurveFitting/ThermalNeutronDtoTOFFunction.h
 	inc/MantidCurveFitting/UserFunction.h
@@ -215,6 +221,9 @@ set ( TEST_FILES
 	StretchExpMuonTest.h
 	StretchExpTest.h
 	TabulatedFunctionTest.h
+	ThermalNeutronBk2BkExpAlphaTest.h
+	ThermalNeutronBk2BkExpBetaTest.h
+	ThermalNeutronBk2BkExpSigmaTest.h
 	ThermalNeutronBk2BkExpConvPVTest.h
 	ThermalNeutronDtoTOFFunctionTest.h
 	UserFunction1DTest.h

Code/Mantid/Framework/CurveFitting/inc/MantidCurveFitting/ThermalNeutronBk2BkExpAlpha.h

@@ -0,0 +1,77 @@
+#ifndef MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPALPHA_H_
+#define MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPALPHA_H_
+
+#include "MantidKernel/System.h"
+#include "MantidAPI/IFunction1D.h"
+#include "MantidAPI/ParamFunction.h"
+
+using namespace Mantid;
+using namespace Mantid::API;
+
+namespace Mantid
+{
+namespace CurveFitting
+{
+
+  /** ThermalNeutronBk2BkExpAlpha : Function to calculate Alpha of Bk2Bk Exponential function from
+    Thermal Neutron Function's Alph0, Alph1, Alph0t, Alph1t, Dtt1, and etc.
+    
+    Copyright © 2012 ISIS Rutherford Appleton Laboratory & NScD Oak Ridge National Laboratory
+
+    This file is part of Mantid.
+
+    Mantid is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    Mantid is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    File change history is stored at: <https://svn.mantidproject.org/mantid/trunk/Code/Mantid>
+    Code Documentation is available at: <http://doxygen.mantidproject.org>
+  */
+  class DLLExport ThermalNeutronBk2BkExpAlpha : virtual public IFunction1D, public ParamFunction
+  {
+  public:
+    ThermalNeutronBk2BkExpAlpha();
+    virtual ~ThermalNeutronBk2BkExpAlpha();
+
+    /// Override
+    virtual void function1D(double* out, const double* xValues, const size_t nData) const;
+
+    /// overwrite IFunction base class methods
+    std::string name()const{return "ThermalNeutronBk2BkExpAlpha";}
+
+    /// Overwrite IFunction
+    virtual const std::string category() const { return "General";}
+
+  protected:
+    /// overwrite IFunction base class method, which declare function parameters
+    virtual void init();
+
+  private:
+    /// Derivative
+    void functionDerivLocal(API::Jacobian* , const double* , const size_t );
+
+    /// Derivative to overwrite
+    void functionDeriv(const API::FunctionDomain& domain, API::Jacobian& jacobian);
+
+    /// Core function (inline) to calcualte TOF_h from d-spacing
+    inline double corefunction(double dh, double width, double tcross, double alph0,
+                               double alph1, double alph0t, double alph1t) const;
+
+  };
+
+  typedef boost::shared_ptr<ThermalNeutronBk2BkExpAlpha> ThermalNeutronBk2BkExpAlpha_sptr;
+
+
+} // namespace CurveFitting
+} // namespace Mantid
+
+#endif  /* MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPALPHA_H_ */

Code/Mantid/Framework/CurveFitting/inc/MantidCurveFitting/ThermalNeutronBk2BkExpBeta.h

@@ -0,0 +1,77 @@
+#ifndef MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPBETA_H_
+#define MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPBETA_H_
+
+#include "MantidKernel/System.h"
+#include "MantidAPI/IFunction1D.h"
+#include "MantidAPI/ParamFunction.h"
+
+using namespace Mantid;
+using namespace Mantid::API;
+
+namespace Mantid
+{
+namespace CurveFitting
+{
+
+  /** ThermalNeutronBk2BkExpBETA : Function to calculate Beta of Bk2Bk Exponential function from
+    Thermal Neutron Function's beta0, Alph1, Alph0t, Alph1t, Dtt1, and etc.
+    
+    Copyright © 2012 ISIS Rutherford Appleton Laboratory & NScD Oak Ridge National Laboratory
+
+    This file is part of Mantid.
+
+    Mantid is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    Mantid is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    File change history is stored at: <https://svn.mantidproject.org/mantid/trunk/Code/Mantid>
+    Code Documentation is available at: <http://doxygen.mantidproject.org>
+  */
+  class DLLExport ThermalNeutronBk2BkExpBeta : virtual public IFunction1D, public ParamFunction
+  {
+  public:
+    ThermalNeutronBk2BkExpBeta();
+    virtual ~ThermalNeutronBk2BkExpBeta();
+
+    /// Override
+    virtual void function1D(double* out, const double* xValues, const size_t nData) const;
+
+    /// overwrite IFunction base class methods
+    std::string name()const{return "ThermalNeutronBk2BkExpBeta";}
+
+    /// Overwrite IFunction
+    virtual const std::string category() const { return "General";}
+
+  protected:
+    /// overwrite IFunction base class method, which declare function parameters
+    virtual void init();
+
+  private:
+    /// Derivative
+    void functionDerivLocal(API::Jacobian* , const double* , const size_t );
+
+    /// Derivative to overwrite
+    void functionDeriv(const API::FunctionDomain& domain, API::Jacobian& jacobian);
+
+    /// Core function (inline) to calcualte TOF_h from d-spacing
+    inline double corefunction(double dh, double width, double tcross, double beta0,
+                               double beta1, double beta0t, double beta1t) const;
+
+  };
+
+  typedef boost::shared_ptr<ThermalNeutronBk2BkExpBeta> ThermalNeutronBk2BkExpBeta_sptr;
+
+
+} // namespace CurveFitting
+} // namespace Mantid
+
+#endif  /* MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPBETA_H_ */

Code/Mantid/Framework/CurveFitting/inc/MantidCurveFitting/ThermalNeutronBk2BkExpSigma.h

@@ -0,0 +1,76 @@
+#ifndef MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPSIGMA_H_
+#define MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPSIGMA_H_
+
+#include "MantidKernel/System.h"
+#include "MantidAPI/IFunction1D.h"
+#include "MantidAPI/ParamFunction.h"
+
+using namespace Mantid;
+using namespace Mantid::API;
+
+namespace Mantid
+{
+namespace CurveFitting
+{
+
+  /** ThermalNeutronBk2BkExpSIGMA : Function to calculate Sigma of Bk2Bk Exponential function from
+    Thermal Neutron Function's Sig0, Sig1, Sig2, Width and etc.
+    
+    Copyright © 2012 ISIS Rutherford Appleton Laboratory & NScD Oak Ridge National Laboratory
+
+    This file is part of Mantid.
+
+    Mantid is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    Mantid is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    File change history is stored at: <https://svn.mantidproject.org/mantid/trunk/Code/Mantid>
+    Code Documentation is available at: <http://doxygen.mantidproject.org>
+  */
+  class DLLExport ThermalNeutronBk2BkExpSigma : virtual public IFunction1D, public ParamFunction
+  {
+  public:
+    ThermalNeutronBk2BkExpSigma();
+    virtual ~ThermalNeutronBk2BkExpSigma();
+
+    /// Override
+    virtual void function1D(double* out, const double* xValues, const size_t nData) const;
+
+    /// overwrite IFunction base class methods
+    std::string name()const{return "ThermalNeutronBk2BkExpSigma";}
+
+    /// Overwrite IFunction
+    virtual const std::string category() const { return "General";}
+
+  protected:
+    /// overwrite IFunction base class method, which declare function parameters
+    virtual void init();
+
+  private:
+    /// Derivative
+    void functionDerivLocal(API::Jacobian* , const double* , const size_t );
+
+    /// Derivative to overwrite
+    void functionDeriv(const API::FunctionDomain& domain, API::Jacobian& jacobian);
+
+    /// Core function (inline) to calcualte TOF_h from d-spacing
+    inline double corefunction(double dh, double sig0sq, double sig1sq, double sig2sq) const;
+
+  };
+
+  typedef boost::shared_ptr<ThermalNeutronBk2BkExpSigma> ThermalNeutronBk2BkExpSigma_sptr;
+
+
+} // namespace CurveFitting
+} // namespace Mantid
+
+#endif  /* MANTID_CURVEFITTING_THERMALNEUTRONBK2BKEXPSIGMA_H_ */

Code/Mantid/Framework/CurveFitting/src/ThermalNeutronBk2BkExpAlpha.cpp

@@ -0,0 +1,89 @@
+#include "MantidCurveFitting/ThermalNeutronBk2BkExpAlpha.h"
+#include "MantidKernel/System.h"
+#include "MantidAPI/FunctionFactory.h"
+
+#include <gsl/gsl_sf_erf.h>
+#include <cmath>
+
+using namespace std;
+using namespace Mantid;
+using namespace Mantid::CurveFitting;
+
+namespace Mantid
+{
+namespace CurveFitting
+{
+
+  DECLARE_FUNCTION(ThermalNeutronBk2BkExpAlpha)
+
+  //----------------------------------------------------------------------------------------------
+  /** Constructor
+   */
+  ThermalNeutronBk2BkExpAlpha::ThermalNeutronBk2BkExpAlpha()
+  {
+  }
+
+  //----------------------------------------------------------------------------------------------
+  /** Destructor
+   */
+  ThermalNeutronBk2BkExpAlpha::~ThermalNeutronBk2BkExpAlpha()
+  {
+  }
+
+  //----------------------------------------------------------------------------------------------
+  /** Defintion of parameter
+    */
+  void ThermalNeutronBk2BkExpAlpha::init()
+  {
+    // Geometry related
+    declareParameter("Width", 1.0);
+    declareParameter("Tcross", 1.0);
+
+    declareParameter("Alph0", 0.0);
+    declareParameter("Alph1", 0.0);
+    declareParameter("Alph0t", 0.0);
+    declareParameter("Alph1t", 0.0);
+  }
+
+  //----------------------------------------------------------------------------------------------
+  /** Function 1D
+    */
+  void ThermalNeutronBk2BkExpAlpha::function1D(double *out, const double *xValues, const size_t nData) const
+  {
+    double width = getParameter("Width");
+    double tcross = getParameter("Tcross");
+    double alph0 = getParameter("Alph0");
+    double alph1 = getParameter("Alph1");
+    double alph0t = getParameter("Alph0t");
+    double alph1t = getParameter("Alph1t");
+
+    for (size_t i = 0; i < nData; ++i)
+    {
+      out[i] = corefunction(xValues[i], width, tcross, alph0, alph1, alph0t, alph1t);
+    }
+
+    return;
+  }
+
+  /** Derivative: use numerical derivative
+    */
+  void ThermalNeutronBk2BkExpAlpha::functionDeriv(const FunctionDomain &domain, Jacobian &jacobian)
+  {
+    calNumericalDeriv(domain, jacobian);
+  }
+
+  //----------------------------------------------------------------------------------------------
+  /** Core function
+    */
+  double ThermalNeutronBk2BkExpAlpha::corefunction(double dh, double width, double tcross, double alph0,
+                                                   double alph1, double alph0t, double alph1t) const
+  {
+    double n = 0.5*gsl_sf_erfc(width*(tcross-1.0/dh));
+    double alpha = 1.0/( n*(alph0+alph1*dh) + (1.0-n)*(alph0t-alph1t/dh) );
+
+    return alpha;
+  }
+
+
+} // namespace CurveFitting
+} // namespace Mantid